DESCRIPTION: (Applicant's Description) In 1995, 34.8% of adolescents reported use of tobacco--a 27% increase since 1991. Only a few studies have evaluated interventions to increase tobacco cessation in this population; research is needed to identify potentially effective strategies for tobacco cessation in adolescents. The applicants propose to conduct a randomized controlled trial to evaluate the effectiveness of a dental screening system with the addition of tailored motivational interviewing and telephone follow-up by a dental hygienist (enhanced systems condition) compared with a dental clinic screening system alone (systems alone), to increase tobacco cessation among all adolescents, ages 14-17, who report at least weekly tobacco use, and to prevent smoking uptake among a limited number of adolescents at risk of smoking. Seventeen dental clinics that are part of a Twin Cities managed care organization will be randomized to either the intervention or comparison condition. Dental staff in all clinics will be trained in a systems approach to tobacco control. Using computerized dental appointment records, all adolescents (n = 6400) with a scheduled dental appointment at these clinics will be identified and screened for eligibility. Eligible adolescents (853 smokers and 100 at risk non-smokers) win complete a baseline telephone interview, and receive enhanced intervention, or not, at the time of their dental appointment according to their clinic assignment. Trained dental hygienists will perform the motivational interviewing, conduct follow-up telephone calls, provide cessation materials, refer adolescents for nicotine replacement therapy, if applicable, and enlist parental support, with the adolescent's permission. Dental charts will be abstracted to document staff compliance with advice against smoking. Follow-up interviews will be conducted with participating adolescents at 3 and 12 months from the time of their dental appointment. The interviews will assess smoking status, validated during the 12 month survey by saliva cotinine, among adolescents in the intervention versus comparison condition, taking into account the clinic as the unit of analysis. Other measures include smoking history, stages of change, self-efficacy, social support for cessation and cessation advice. In addition, a cost-effectiveness analysis will be conducted to determine the potential for dissemination of the intervention, if effective.